Sponges

While corals have long been recognised as archives of ocean conditions, we are now also exploring the possibility to use sponges as archives of deep ocean conditions. Monoraphis chuni is considered most suitable because this sponge grows in concentric rings with good understanding of growth pattern, and it contains up to 1000 concentric rings. If we can prove that these rings are annual layers then this may open the potential of long records with annual resolution.